This invention relates to a method and apparatus for vibration welding at least three (3) separate component pieces within one (1) vibration weld fixture assembly.
Traditionally, a vibration weld fixture assembly includes a fixed upper tool for holding a first part and a fixed lower tool for holding a second part. The upper and lower tools clamp opposing faces of the first and second parts together for a single welding operation. During this welding operation a weld machine upper platen applies a sideways oscillation to the upper tool to generate the necessary friction between the first and second parts to provide the desired weld, forming a first component assembly.
If a third part is subsequently to be welded to the first component assembly including the first and second parts, the first component assembly is removed from the first vibration weld fixture assembly and then placed in a second vibration weld fixture assembly. The second vibration weld fixture assembly also includes upper and lower tools, which clamp a weld face on the third part to a weld face on the first component assembly for a second welding operation. The weld machine upper platen applies a sideways oscillation to the upper tool to generate the necessary friction between the third part and the first component assembly to provide a second weld, resulting in the formation of the final assembly of three pieces. Thus, in order to weld three (3) separate parts together with two welds, two (2) separate weld machines and two (2) separate weld fixture assemblies are required, which is expensive. Further the necessity of moving parts between the different weld fixture assemblies increases assembly time and cost.
Thus, it is desirable, to provide a method and apparatus for performing multiple welding operations for at least three parts within a single weld fixture assembly to reduce cost and assembly time, as well as overcoming the other above mentioned deficiencies with the prior art.
A vibration weld fixture assembly provides the formation of a multiple piece component in a single weld fixture assembly. A movable tool portion positions the separate component pieces relative to one another so that the pieces can be joined together by consecutive welding operations.
Preferably, the vibration weld fixture assembly includes fixed upper and lower tools that support first and second component pieces, respectively. A center tool, movable relative to the upper and lower tools, moves a third component piece into engagement with one of the first or second component pieces for a first vibration weld operation. The center tool then moves the third component piece into engagement with the other of the first or second component pieces for a second vibration weld operation.
In a preferred embodiment, an actuator assembly moves the center tool back and forth between the upper and lower tools. The actuator assembly includes a first linear actuator mounted to one of the upper or lower tools and a second linear actuator mounted to the other of the upper of lower tools. The first and second linear actuators selectively engage an adaptor mounted to one end of the center tool to move the center tool to a desired position between the upper and lower tools.
Preferably, a controller generates a control signal that is sent to the actuator assembly. The control signal positions the center tool at the desired location and determines clamp pressures between the first, second, and/or third component pieces for the vibration welding operations based on predetermined characteristics. For example, the controller varies clamp pressures between the component pieces based on component weight, tool weight, and weld area.
The method of vibration welding a three-piece component within a single vibration weld fixture assembly having an upper tool, a lower tool, and a center tool positioned between the upper and lower tools includes the following steps. A first component piece is loaded into the lower tool, a second component piece is loaded into the upper tool, a third component piece is moved into engagement with one of the first or second component pieces via the middle tool, and a first vibration weld is performed. Subsequent steps include moving the third component piece into engagement with the other of the first or second component pieces via the middle tool and performing a second vibration weld.
The subject apparatus and method provides single vibration weld fixture assembly that is capable of forming a multiple piece component with multiple welding operations. These and other features of the present invention can be best understood from the following specifications and drawings, the following of which is a brief description.